In the Linux kernel, the following vulnerability has been resolved:
scsi: target: iscsit: Free cmds before session free
Commands from recovery entries are freed after session has been closed. That leads to use-after-free at command free or NPE with such call trace:
Time2Retain timer expired for SID: 1, cleaning up iSCSI session. BUG: kernel NULL pointer dereference, address: 0000000000000140 RIP: 0010:sbitmap_queue_clear+0x3a/0xa0 Call Trace: target_release_cmd_kref+0xd1/0x1f0 [target_core_mod] transport_generic_free_cmd+0xd1/0x180 [target_core_mod] iscsit_free_cmd+0x53/0xd0 [iscsi_target_mod] iscsit_free_connection_recovery_entries+0x29d/0x320 [iscsi_target_mod] iscsit_close_session+0x13a/0x140 [iscsi_target_mod] iscsit_check_post_dataout+0x440/0x440 [iscsi_target_mod] call_timer_fn+0x24/0x140
Move cleanup of recovery enrties to before session freeing.